1. Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA.
2. Structural Bioinformatics Core Facility, University of North Carolina, Chapel Hill, NC 27599, USA.
3. Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
4. Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
5. School of Biological Sciences and Plant Science Initiative, University of Nebraska, Lincoln, NE 68588–0660, USA